Re: [PATCH] [RFD] Add repoid identifier to commit

["Sean" <seanlkml@sympatico.ca>]

On Wed, May 11, 2005 5:38 pm, Thomas Gleixner said:
> This is an initial attempt to enable history tracking for multiple
> repositories in a consistent state. At the moment this can only be done
> by heuristic guessing on the parent dates and the committer names.
> This fails for example with Dave Millers net-2.6 and sparc-2.6 trees, as
> in both cases the committer name is the same. It fails also completely
> in cases where the system clock of the committer is wrong and the merge
> is a head forward. The old bk repository contains entries from 1999 and
> 2027, which will happen also with git over the time.
>
> To identify a repository commit-tree tries to read an environment
> variable "GIT_REPOSITORY_ID" and has a fallback to the current working
> directory. The environment variable keeps the door open for managed
> repository id's, but the current working directory is certainly a quite
> helpful information to solve the origin decision for history tracking.
>
> Adding a line after the committer should not break any existing tools
> AFAICS.

To make this useful you're also going to have to change the parent entries
to something like:

parent SHA1 REPOID

At least when the referenced commit has a repoid that doesn't match the
repository from which you obtained the object, ie. fast forward heads. 
This implies that you know the repoid of the repository you pulled the
object from!

Otherwise, you still haven't solved the problem of identifying fast
forward heads as you traverse the history.

Sean